Package encoding provide capabilities to convert data to and from byte-level and textual representations.
- encoding/gob
- encoding/json, and
- encoding/xml
The gob is Go’s format for serializing and deserializing. The gob was tailored for communicating between two servers written in Go.
- Only exported fields are encoded; zero values are not taken into account
Package gob manages streams of gobs – binary values exchanged between an Encoder (transmitter) and a Decoder (receiver).
Format GoB#
Let’s create a simple Type Blog and we will encode and decode it using the gob format.
package enc
import (
"encoding/gob"
"flag"
"fmt"
"log"
"os"
)
// Blog blog structure
type Blog struct {
Title, Author, Category string
Length int
}
func (b *Blog) String() string {
return fmt.Sprintf(" Blog: %s @ %s\n Category: %s\n Length: %d", b.Title, b.Author, b.Category, b.Length)
}
var fileName string
var logger = log.New(os.Stdout, " ENC: ", log.LUTC)
func init() {
flag.StringVar(&fileName, "f", "", "Output/Input file")
flag.Parse()
}
const (
//ErrorMessage For the errors
ErrorMessage = "need a file to write or read the contents."
)
var defBlog = Blog{Title: "My first blog", Author: "Samarthya", Category: "technical", Length: 200}
// Cmd main entry method
func Cmd() {
if flag.NFlag() == 0 {
flag.PrintDefaults()
logger.Fatalf("%s", ErrorMessage)
}
f, err := os.OpenFile(fileName, os.O_CREATE|os.O_RDWR, 0666)
defer f.Close()
if err != nil {
logger.Fatalf("%s", err.Error())
os.Exit(1)
}
enc := gob.NewEncoder(f)
err = enc.Encode(&defBlog)
if err != nil {
logger.Fatalf("%s", err.Error())
os.Exit(1)
}
dec := gob.NewDecoder(f)
var blogR Blog
f.Seek(0,0)
err = dec.Decode(&blogR)
if err != nil {
logger.Fatalf("%s", err.Error())
os.Exit(1)
}
fmt.Printf(" Read: %s\n", blogR.String())
fmt.Println(" --- End Program -- ")
}./main -f abc.txt
Read: Blog: My first blog @ Samarthya
Category: technical
Length: 200
--- End Program --